The invention relates to a windshield wiper drive for vehicles, in particular for rear windshield wipers of vehicles.
Windshield wiper drives for vehicles are known from practice in embodiments in which the output shaft leading to the windshield wiper is supported in a drive housing, which is located behind a cover, for example also a windshield, which is penetrated by the output shaft. The output shaft is in this region enclosed by a protective cap, which is supported relative to the housing and which at the end remote from the housing sealingly bears against the output shaft.
The encompassing arrangement of the cover relative to the protective cap, due to tolerances of the vehicle and in the arrangement of the windshield wiper drive, may lead to loading of the protective cap which impairs the sealed connection of the protective cap relative to the output shaft, particularly during operation of the windshield wiper, and dynamic forces may occur, in particular in the return positions, which may also have a negative effect on the sealed connection of the protective cap relative to the output shaft.
The object of the invention is to prevent negative effects on the sealed connection of the protective cap relative to the output shaft, by such loads acting on the protective cap.
In the windshield wiper drive according to the invention, the protective cap is radially supported in the transition between its end regions, i.e. in the transition of its support relative to the drive housing and its sealed connection relative to the output shaft provided at the other end. This takes place, in particular, by bridging over the radial gap between the output shaft and the protective cap, via a support bearing supported against the output shaft, so that forces acting on the protective cap—in particular in the region of its penetration of a cover—may be absorbed by the support bearing and have no effect on the sealed connection of the protective cap relative to the output shaft.
The sealed connection of the protective cap relative to the output shaft is formed, in particular, by a sealed arrangement associated with the protective cap, preferably an annular seal, namely an O-ring.
The support of the annular seal takes place axially by a retaining element, in particular an annular retaining element, which is axially secured to the protective cap in a locking manner and in a tensioning manner.
The support bearing is preferably configured as a supporting sleeve and axially secured to the protective cap via an annular collar. This annular collar is expediently located between a spring-loaded shoulder of the protective cap and a latching shoulder which is associated with the protective cap and able to be passed over, and which may be designed as an inwardly curved bead, so that with a corresponding radial elasticity of the protective cap, consisting preferably of plastics, or of the annular collar, the fixing of the support bearing may be achieved without tools and without additional parts.
The support of the protective cap via the support bearing preferably takes place in a region of the protective cap, in which said protective cap is supported, in particular sealingly, against an encompassing component, whether a cover or a windshield.
If the windshield wiper drive according to the invention is used in combination with rear windshields of vehicles for rear windshield wipers, the drive housing is located inside the windshield and the windshield is penetrated by the output shaft, a preferably annular sealing element being arranged between the windshield and the protective cap and the entire arrangement possibly requiring long output shafts with a long overhang for support on the housing side, so that the partial stiffening of the protective cap according to the invention via the supporting sleeve is particularly advantageous.